Burner control apparatus



May 22, 1945.

R; LONGINI 2,376,496

BURNER CONTROL APPARATUS Filed Aug. 13, 1941 RICHARD L. LONGINI,

INVENTOR,

Patented May 22, 1945 2,376,496 BURNER conraonarrmrtis Richard 1.. Longini, Chicago, m., assignor; by

mesne assignments, to Wheelco Instruments Coimpany, Chicago, 111., a corporation of lllino s Application August 13, 1941, Serial No'. 405,828 1 Claim. (Cl. 158-28) This invention relates to safety apparatus for preventing the operation of a burner when the game supervisory apparatus is in unsafe condi- In burner control apparatusYprovided with a control circuit and a flame switch for controlling the fuel supply inaccordance with themesence or absence of flame, it is highly important, in event that the flame switch is in unsafe condition (e. g, when there exists a leakage, between electrically operated gas valve 6 supplying burnn, and fixed contacts 2s, 2s, 2s and 2s. The relay 22, through its contacts, is connected to an er 3 with fuel, to an ignition transformer 5 and an electrically operated valve 1 for the pilot burner 4, to a safety relay l2 and a push button switch electrode circuit and ground, of about the same resistive order as the flame, in which event the circuit would respond asif a flame were present and open the fuel supply), to prevent starting while such condition exists, even when anactual attempt is made to start the burner.

The primary'objectof this invention is'accordingly to provide a means for preventing such starting in a burner control apparatus of the. 1

character referred to above when the flame switch is in unsafe condition.

Other and further objects of this invention will become more apparent hereinafter as the same becomes better understood from an examination of the specification, and claim in conjunction with the accompanying drawing wherein is shown diagrammatically and schematically a burner control apparatus including safety means embodyin this invention.

Referring to the drawing more particularly, reference character I designates a flame electrode of the same general type shown in patent to W. H. Gille, No. 2,231,420 of February 11, 1941,

for Burner control system or as shown in the copending application of Theodore A. Cohen, Richd L. Longini and Hans J. Ostermann, Ser. No. 274,904, filed May 22, 1939, for Burner control apparatus. The electrode I is provided with a flame rod 2 for contacting a flame from a pilot gas burner 4 and a main gas burner 3. The electrode l is connected by a cable ill to an input terminal 32 of a flame switch apparatus 20. This flame switch apparatus corresponds to the electronic apparatus shown and described in the aforesaid copending application but may be any variety of In so that these valves and ignition transformer will be opened and turned on automatically when push button I0 is depressed and a flame is present thereafter at either burner. If the flame switch is in unsafe condition so as to cause the pulling up of relay 22, for'any reason such, for example, as the existence. of a leakage between the electrode circuit and ground of the resistive order of the flame, it would be most unsafe to start the burner because of open condition of valve 6. In order to prevent the burner from starting when such an unsafe condition of the flame switch exists, even though the push button is depressed in an attempt to start the burner, I provide the particular arrangement to be hereinafter described.

The safety relay l2 includes a coil l1, movable contacts I! and i5 and fixed contacts l4. and

The push button switch I0 is adapted to be manually operated to start the burner and includes contacts 30, 29 and 3| and a manually operable member 34 for connecting said contacts together. when depressed. Contact is.

- valve I to side lab of the line. Contact 3| goes to a lead 38 connecting to coil ll. The other side flame switches -well known in the art. Reference number 33 designates the other output terminal of the flame switch electronic apparatus 20 which is grounded so that the input circuit to said apparatus may be completed by the presence of a burner flame in either the pilot burner 4 or the main burner 3. The Output of the flame switch apparatus 20 is'connected to energize coil 2| of a relay mechanism 22. The relay 22 includes an armature, which carries movable contacts 24 and of coil ll goes to side Nb of the power line.

Analarm bell II is adapted to be energized when the flame at the burner is extinguished and the relay 22 automatically opens.

Reference character It designates the electri cal power line comprising the two sides thereof ltd and I 8b and numbers 8 and 9 refer to the pilot and main burner fuel supply lines, respectively. Y

Ignition transformer ,5 and electrically operated pilot valve I are connected in parallel from side lib of the power line It to contact 29 of the Push button It. Contact 30 thereof is connected tocontact 26 of relay 22. Sincecontact 21 of relay 22 is connected to side lta of the power line, transformer 8 and valve 1 will he energized upon depressing the push button Ill but only if relay 22 relay 22 -is open. Contact Si is connected through coil l1 of relay l2 to side l8b of the powor supply and contact 30 being connected to side l8a through contacts 28 and 21 when the push button In is-depressed, relay 12,, will pull up and close but, likewise, only if relayv 22 is open at and before time of starting. l

The contacts is and I6. of relay l2 are in parallel with-contacts 26 and 21 of relay 22 whereby, when relay l2 closes, the latter contacts may be broken, upon the subsequent pulling up of relay l2, and the ignition transformer I and pilot valve I will remain, on, so long as the push button In v is depressed.

The main burner electrically operated gas valve I is connected from side iBboi' the power line through contacts 25 and 24 of relay 22 and thence 22 (due to unsafe condition of the flame switch 20), before closing of relay l2, would prevent any start whatever by preventing the subsequent closing of relay l2 to thereby prevent energizing transformer-S, pilot valve 1 and coil l1 of relay l2,

all of which have to be energized for a start at-.

tempt through contacts 28 and 21 of relay 22.

s In order to prevent relay l2 from dropping out" after a safe start has been made upon subsequent closure of relay 22 due to presence of flame, and after the push button ID ,has been released, said relay I2 is locked closed by virtue of another connection being provided for energizing coil l1' other than the connection through said push button which was previously described. This locking connection forjenergizing coil i1 is dependent upon both relays i2 and 22 beingclosed in proper sequence (relay l2 first) and consists of a conductor 35 connected from said coil, at the side thereof opposite to side lib of the line supply, to 'sidelie of the line supplythrough contacts I! and I4 of relay l2 and contacts. 21 and 28 of relay 22.

A flame failure or ground out will act, as described in'the aforesaid copending application, to

open to shut off the fuel supply to the main. v bumer when relay 22 is automatically opened by the flame switch 20 on account of flame failure or ground out as described in the aforesaid copending application. v j

The opening of valve. 8 allows fuel to main .bumer 2 which flres from pilot 4 whereupon transformer and pilot valve 1 are deenergized by the release of push button 10. The main flame from burner) striking electrode 2 maintains the system.

The alarm II is connected across opposite sides of the powerline "through contacts 22 and 24 and through contacts 28 and 21 so that when relay 22 is open the alarm will be sounded to indicate. the absence of flame at the burner.

- The pilot burner. may take any of the usual forms and is here shown of a type such as disclosed in the copending application of Richard L.

Longini, Ser. No. 330,157, flied April 1'1, 1940, for Burner.

' Operation In the operation of the apparatus, push button It is depressed to energize transformer 5 and. pilot electric valve 1, through contacts 28 and 30 of the push button and through contacts 28 and 21 of relay 22, from the line-ll. At the same time relay coil I1 ofrelay I2 is energized through push button contact 3| to close said relay. A flame appears at pilot burner 4 which contactsrod 2 whereupon the flame switch 20 pulls up its relay 22 to make contacts 24 and 25 broken, upon pulling up'of relay 22, the ignition transformer 5 and pilot valve 1 remain on by virtue of contacts l5 audit in relay l2 as long as the push button is depressed. The making of contacts 24 and 25, upon closing of relay 22, energizes the main gas valve through closed contacts l5 and it of relay l2. The opening of valve 8 allows fuel to flow to'main burner 2 which is ignited by the flame at pilot burner 4. Upon releasing the push button l0. ignition transformer I and pilot electric valve 1 are deenergized whereupon the pilot flame at burner 4 is extinguished leaving the system maintained by the flame from main burner 3 impinging upon the flame rod 2.

Should a flame failure occur, or should the system be grounded out, as described in the .flrst of the aforementioned copending applications, the relay 22 is deenergized to break contacts 24 and 25 and to break contacts 28 and 21. At the same time contacts 23 and 24 and contacts 26 and 21 are made. The breaking of contacts 21 and 28 of relay 22, as well as the breaking of. contacts 24 and 25, deenergizes main fuel supply valve 8 which stops fuel supply to main burner 8.

The making of contacts 22 and 24 and the making of contacts 26' and 21 energizes alarm l I to indicate, audibly, that there has been a flame failure, or ground out..

The above describes normal functioning of the I 'and the ground of substantially the same resistive order as that of the flame, apparatusheretoiore used would be unsafe, inasmuch as valves such as 6 would be held open even when' flame were absent. In this apparatus, when such leakage exists between flame rod 2 and ground, or from the electrode circuit to ground, the flame switch relay 22 will be held in closed position so that contacts 22 and 24 and contacts 24 and 21 are broken while contacts. and 25 and contacts 21 and 2 8 are made. Under these conditions, de-, pressing push button In, in an attempt to start the system, can perform no operation because. the contacts 28 and 21 being broken, the coil l1 of relay I2 cannot beenergized nor can the ignition transformer 6 or the pilot electric valve .1

21, iii-preventing energization of coil l1 or re-. sultant closing of relay l2 and the latters contacts ii' and it, thus prevents energizing of the main fuel valve .6.

Thus, in summary, if the safety relay I2 is not.

energized upon a starting attempt being made.

i for heat. Obvious asvs sec due to previous leakage in the fiame switch sysbe added to any wariety' of manually or semiautomatically started flame supervisory systems to insure safe operation in event of any leakage which in efiect would maintain the flame switch closed during flame absence or ground out.

The aforedescribed system is set in operation or removed from operation, as required, by a switch 40 which may be manual or may be automatic in the form of a pressurestat or a thermostat, e. g. like the switches l! or II in the aforesaid co-pending ap lication, in response to a call opening 01' switch 40, when heat is no longer desired, will cause the system, including fuel supply valve 8,. to shut down.

- I am aware thatmany ,thanges may be made principles oi my invention and I therefore do not age path having a like resistance. said mechanism including a relay adapted, to be energised when said circuit is-completed, switch means operahlell-iy said relay to close when the relay is de- 7 and details varied without departing from the wish tobe limited to the details shown or described.

I claim:

The combination of a burner, a fiame switch mechanism operable by an electric circuit responsive to and capable or being completed through a energized. and to open when the relay is energised, a second relay having an operating coil and switch means adapted to be closed when said coil is energized, ignition means for the burner, s starting switch, an electric burner fuel supply valve, a source oi electrical energy, connections for energizing said coil from said source through said starting switchand said first switch means, only when the latter is closed. and thereafter, upon closure or the second switch means, :to ener-g gize said coil through said second switch means in lieu oi" through the starting switch (but still through the first switch means) connections for energizing said ignition from said source whenthe starting switch is closed and the first switch means is closed, supplemental switch means operable by the first mentioned relay to close when said first relay is energized and connections for energizing said fuel supply valve through said last mentioned switch means and the second mentioned switch means only when both are closed.

RICHARD L. LONGINL' 

